CAR Trip of a Lifetime: Immune System to Destroy Specific Cancer using CAR: Trial in Pancreatic Cancer and A Video Modified T Cells in Chronic Lymphocytic Leukemia
Have They Found a Powerful Method that Really Works to Get the Immune System to Attack Specific Cancers?
What Does a CAR Have to do with Cancer Therapy? : Souped Up T Cells
The creative types that lurk in labs have long been trying to harness the body's immune system to attack specific cancer cells the way we fight disease like polio or infections like influenza. For example, cancer vaccines.
The NY Times had another remarkable story about the creation of "doctored" or "souped up" genetically engineered T cells,chimeric antigen receptor T cells, to teach a person's immune system to destroy a specific cancer . A CAR is a protein composed of an antibody that can bind to a known target together with another part that triggers the T cell to destroy the target.
What are Chimeric Cells and What Good Are They?
Bone Marrow Transplants have been used against leukemia. In contrast, these chimeric antigen receptor T cells were designed to have wider application and more benefits such as prolonged activity. Killer T cells are attractive for gene therapy, because they can last lifelong. So if you can make a T cell become cancer specific, then the potential is that the patient can have lifelong protection from that because the T cells are long lived cells. The concept of doctoring T-cells genetically was first developed in the 1980s by Dr. Zelig Eshhar at the Weizmann Institute of Science in Rehovot, Israel.
"Chimera is a Greek word for an animal of two species fused together. A CAR is a protein composed of an antibody that can bind to a known target along with a fusion partner, the other part of the CAR, that contains the business end—it’s basically the engine that activates the T cell and tells it to kill the tumor cell that it’s bound to, and also makes the T cell proliferate.
What are T Cells ?Our immune system destroys "enemy" cells like infections by recognizing the foreign chemical markers ,the antigens on the surface of the foreign invader cells. An antigen is a substance, a chemical marker or signal on the surface of the "enemy" foreign cell that is invading the body, The antigen marker when recognized by the immune system leads to the production of one or more antibodies. Antibodies are the body's roving defense system against infection and disease elements.
T cells are one part of the body's defense system involved in the immune system.
The cancer therapy uses modified T cells that can target specific cancers. But what are T cells? T cells belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They mature in the thymus gland. T cells can be distinguished from other lymphocytes, such as B cells and natural killer cells (NK cells), by the presence of a T cell receptor (TCR) on the cell surface.
What Are Antigens ?
An antigen is a substance that evokes the production of one or more antibodies. Antibodies are the body's roving defense system against infection and disease elements. Each antibody binds to a specific antigen by way of an interaction similar to the fit between a lock and a key. Our immune system destroys "enemy" cells like infections by recognizing the foreign chemical markers ,the antigens, on the surface of the foreign invader cells. The substance may be from the external environment or formed within the body (aka rheumatoid arthritis). So an antigen is a kind of chemical signal or marker on a cell surface.
According to Dr. Carl June, "Chimera is a Greek word for an animal of two species fused together. A CAR is a protein composed of an antibody that can bind to a known target —in our model we picked the CD19 antigen found on B cell leukemias. The fusion partner, the other part of the CAR, contains the business end—it’s basically the engine that activates the T cell and tells it to kill the tumor cell that it’s bound to, and also makes the T cell proliferate. So the CAR does two major things:
1. It makes the T cell become leukemia specific, and
2. It makes the T cells divide when they encounter a tumor cell".
"To make T-cells search out and destroy cancer, researchers must equip them to do several tasks: recognize the cancer, attack it, multiply, and live on inside the patient. A number of research groups have been trying to do this, but the T-cells they engineered could not accomplish all the tasks. As a result, the cells’ ability to fight tumors has generally been temporary".
CAR Against Pancreatic CancerThe method which has been targeted at leukemia will be targeted at pancreatic cancer. It involves adding gene sequences from different sources to enable the T-cells to produce what researchers call chimeric antigen receptors, or CARs — protein complexes that transform the cells into “serial killers.” Serial killers because the Transformed T cells kill multiple cancer cells.
as functional receptors with antibody-type specificity